1. Field of the Invention
The present invention relates to an X-ray thin film inspection apparatus suitable for a technical field of manufacturing a device having a multilayer film structure achieved by laminating many thin films on a substrate, such as a semiconductor manufacturing field.
2. Description of the Related Art
With respect to semiconductor devices or other types of devices in which a multilayer film structure achieved by laminating many thin films is formed on a substrate, the characteristics of these devices are varied in accordance with the film thickness, density, crystallinity, etc. of each thin film to be formed. Recently, the miniaturization and integration of these devices have been advanced, and this tendency has been remarkable. Therefore, a thin film inspection apparatus that can accurately measure the state of each film thus formed has been required.
Direct measurement by a sectional transmission electron microscope (TEM), a film thickness inspection apparatus using optical interference or ellipsometry, an opto-acoustic type apparatus, etc. have been hitherto known as this type of inspection apparatuses. With respect to the sectional transmission electron microscope (TEM), it is an actual condition that it is impossible to install the sectional transmission electron microscope in a manufacturing process and examine a thin film as an inspection target on a real-time basis, and also a product which is taken out from the manufacturing line for an inspection is discarded after the inspection. Furthermore, the film thickness inspection apparatus using optical interference or ellipsometry and the opto-acoustic type apparatus are suitable for the in-line process, however, the measurement precision thereof is too low to measure the thin film of several nm.
Wafers for inspection (blanket wafers) which are used once for inspection and then thrown away are a large cost load for semiconductor device makers. Particularly, the diameter of semiconductor wafers has been increased, and the cost needed for one blanket wafer has been also increased.